Regarding a cutter installed in a cutting device in which to cut sheets by sliding a cutting blade, a holder retaining a circular cutting blade is generally installed at a slider that is allowed to travel in the cutting direction thereof. In such a cutter, the holder is rotatively provided at the slider. By supplying a cutout to the holder, the cutout making the cutting edge of the cutting blade partially exposed, when exchanging the cutting blade, the holder is rotated so as to shield the cutting edge. This technique is disclosed in Patent Document 1 (see below).
When the cutting blade is exchanged, the holder is removed from the slider. The cutting blade is then taken off from the holder for exchanging with a new cutting blade. Here, from a locked condition that a projection portion provided at the outer periphery of the holder is secured at the slider, a lever is operated so as to release the locked condition. A dial is then operated so as to rotate the holder. Accordingly, the cutting edge of the cutting blade is shielded with the holder.
In addition, in order to exchange the cutting blade without touching thereof, Patent Document 2 (see below) has proposed a so-called cassette-type cutter that allows exchanging the whole holder retaining the cutting blade to a new holder.    [Patent Document 1] Japanese Patent Application Laid-open No. Hei 9-123088    [Patent Document 2] Japanese Patent Application Laid-open No. 2002-239266